Making open-hearth-furnace bottoms



March 1o, 1925.

H. M` sHAAB MAKING OPEN HEARTH FURNAC BOTTOMS Filed Fel;L 4 sheets-snaai v1 in, @f

H. M. SCHAAB MAKING OPEN HEARTH FURNACE BOTTOMS Mmh 1o, 19,25. 1,529,219

Filed .Febl 2l- 1920 4 Sheets-Sheet 2 March l0, 1925.

H. M. SCHAAB MAKING OPEN HEARTH FURNACE BOTTOMS Filed Feb. 2l. 1920 4 Sheets-Sheet 3 7 vg/M? March 10, 1925.

H. M. SCHAAB MAKINGOPEN HEARTH FURNACE BOTTOMS 4 sheets-sheet 4 Filed Feb. 2L 1920 Patented M. 10,1925.

UNITED sTATEs HARRY 0F YOUNGSTOWN, DHIO. ASSIGNOR OF ONE-HALF T0 W. BRUCE OGDEN, 0F YOUNGSTOWN, OHIO.

MAKING OPEN-HEARTH-FURNACE noir'rons.

Application med February 21, m2o. serial No. 360,468.

To all whom #may concern.'

Be it known that I, HARRY M. SoHAABfa citizen of the United States, residingl at Youngstown, in the county of Mahoning and State of Ohio, have invented a new and useful Improvement in Making Open-Hearth- Furnace Bottoms, of which the following is a full, clear, and exact description, reference being had to the accompanyingv drawings, formingpart of this specification, in which-,- 7 Figure l1 is a side elevation partly in section of one form of apparatus in which the invention is embodied.

Figure 2 is a plan view of the apparatus shown in Figure 1.v

Figure 3 is a vertical section along the line III-III of Figure 2.

Figures 4-.and 5 arediagi-ammatic views of an open hearth furnace showing the ap-v plicationthereto of the crushed dolomite, Figure 4 being a vertical section adFgure 5 being a. horizontal section through the open hearth furnace, and v Figure 6 is a side elevation of a modified form of apparatus embodying the invention. The present invention relates to making open hearth furnace bottoms, and more particularly to the building up of the furnace bottom with crushed dolomite between heats.

i In making steel by the open hearthfurnace process, a pool or bath of metal is heated in the open hearth furnace. The bottom ,Of the furnace is lined with dolomite sothat the metal is subjected to the action of the basic dolomite. During the heat more or less of the dolomite is melted into slag, so that'aftei` a heat is tapped from the furnace, the dolomite bottom ofthe furnace has to .be renewed. y

Thel present invention relates to the making of the furnace bottoms mechanicall and has for its object the doing awa wit the hand labor heretofore employ and for making the furnace bottoms much more quickly and economically.

In making a furnace bottom I apply the dolomite b means of compressed air. The dolomite 1s projected into thev vfurnace through a nozzle which ma be so manipulated as to throw or spray t e dolomite over the furnace bottom. During the bottom making operation, the heat is maintained on the furnace so that the bottom is maintained in a uxed or semi-fused condition, so that the small pieces of crushed dolomite stick "usually used the ho raw dolomite is ma e'somewhatlarger than the hopper 13 which holds thezburned dolo-l against and become fusedf to the point on the furnace bottom against which the stream of dolomite from the nozzle is directed.

Referring first to Figures 4 and 5, an open hearth furnace 2 is diagrammatically illustrated therein. The furnace has the bottom 3 of dolomite, Figures 4 and 5 diagrammatically showing the making of such bottom. The crushed dolomite is thrown or projected into the furnace from'a nozzle 4 by means of a. stream of compressed y,air forced through the nozzle. As shown in Figures 4 and 5, the stream or spray 5 of crushed dolomite, indicated in dotted lines, may be directed as desired against the bottom of the furnace, to

build up the usual furnace bottom to hold the bath of molten steel.

As shown in Figures 4 and 5. the nozzle 4 is directed through the usual door 6 in the side of the furnace. During the spraying of the dolomite into the furnace, the furnace is stronglv heated by the usual gas flame, so

' that thel dolomite is fused or sintered into an integral furnace bottom capable lof holding the bath of metal. The heat holds t-he bottom vwhich is already laid in a lsticky semil fused condition, so that the pieces of dolomite, 'as they are, thrown in by ,the compressed air, lodge against such surface and.l

are held therebyandthen become fused into the furnace bottom. In this Way the furto the furnace bottom.n `In this form of the.

vnace bottom is quickly built up into thede- 'Y apparatus the ldolomite'fis carried in a hop-y per car 10 which "runs on theusual rails 11 in front of the open hearth furnace .or furli naces. `The Canis rovided withtwo hopdolomite are usually used' in 1na king a furnace bottom. Since more" raw dolomite "i`s'1 per 12. for holding the mite. The hoppers 12 and 13 are provided at their bottoms with valves or'gates 14 and 15, respectively, through which the dolomite may be drawn into the ap aratus which feeds it to the furnace. The opp'ers 12 and 13 open to a screw-conveyor 16 which-'feeds motor 19 carried on the car. Y

The dolomite as it falls through the feed ytube 17 into the air tube 18 is picked up 'and carried in the air tube 'by means ofa stream of compressed air. The compressed air is supplied 'to the air tube 18.'by means of a pipe 20 which is connected with the compressed air supply of the Steel pjlant,

Air under fifty to one hundred pounds pressure is usually available. The'streamof air and dolomite asses through a flexible hose,

usually aV flexible steel hose, to the nozzle 4 from which the stream of dolomiteis thrown or shot forcibly into the furnace.-

The flexible `hose 21 ermits the nozzle to be manipulated as desired by the operative...

infront of the furnace to be bottomed. The' 'roper amount and kind of dolomite is fed y the manipulation of the valves 14 and 15 at the bottom of the'hoppers. The screw conveyer 16 feeds the dolomite evenly to the compressed air plpe, and the compressed air projects or sprays the dolomite in a stream which is directed at will by the o erator. Asshown in the drawings, the nozz e l14 is preferably flattened so that the stream of olomite is spread outsomewhat, as it is found that `it is thus best applied to the furnace bottom.

In Figure 6 is illustrated a modification in which the hopper holding the dolomite is arranged to be swung; from a crane instead of carried on a car. As shown. in Figure 6 a single hopper is provided. ghis hopper 30 is provided with trunnions 1 by means of which it may be supported by an overhead crane. T l1e dolomite is fed through a feed pipe 32 controlledby la manually operated valve 33 into the pipe 34 through which compressed air is rapidly passing. The compressed air is supplied by means of a iexible hose connection v35, from .the compressed air system of the steel plant. The nozzle 4 is carried onthe end of a flexible hose 21 substantially as illustrated in Figures .11 and 2. The'end of the hose 21 is supported on an arm 42 pivoted to the side of the hopper and raised or lowered by means of a rope 43 controlled by a hand windlass 44.

I have described the building up of the furnace bottom from dolomite because dolomite is the material now universally employed in making furnace bottoms. It is tovbe understood, however, that the invention is no-t necessarily limited to the specific material, dolomite, but might be employed with other materials-if other materials are used for making furnace bottoms. The termfdolomite therefore, as employed in the specification and claims is intended as a term of description and not of limitation, and to include vdolomite or equivalent materials which might, be used in making furnace bottoms.

While I have specifically illustrated and described the preferred embodiment of my invention, it is to be understood that the invention is not limited to such embodiment but may be otherwisel embodied within the scope of the following claims.

1. The method? of making open hearth furnace bottomsfwhich l consists in directing a stream of gaseous fluid into the furnace and against' the portion of the furnace which is to be repaired from a pointloutside the furnace, and introducing crushed dolomite to the stream while maintaining a dolomite fusing heat in the furnace, the dolomite being .introduced to the Huid stream in suchl manner that all particles of the dolomite will be immediately subjected to the action of the fluid stream, substantially as described. Y

2. `The method of making open hearth furnace bottoms which consists in directing a stream of compressed air into the furnace from a point outside the same, and introducing a stream of crushed dolomite into the stream of compressed air while maintaining a dolomite fusing heat 1nto the furnace, the stream of compressed air being at least .as wide as the stream of crushed dolomite, substantially as described.

- In testimony whereof I have hereunto set my hand.

' HARRY M. SCHAAB. 

